Re: st: Count number of observations in date range

["Sebastian F. B�chte" <sfbuechte@gmail.com>]

Austin,

it would be very helpful for me if you could point out in more detail
where my code fails to identify an overlap. I admit that I somehow
assume that the entries in the "event" variable uniquely identify
observations. If this was not the case I would miss overlaps. But,
under this assumption I cannot figure out which overlaps I would miss.

Regards
Sebastian

On 4/19/07, Austin Nichols <austinnichols@gmail.com> wrote:
> Jarl Svartsj� --
> I don't think that Sebastian's code deals with all overlaps.
> Another approach would be to loop over observations, which I outline below.
>
> clear
> input event start end
>        1  16081 16108
>        2  16081 16109
>        3  16084 16092
>        4  16091 16143
>        5  16100 16105
>        6  16109 16143
>        7  16110 16110
> end
> format st end %d
> li , noo clean
> g long nsimul=.
> forv i=1/`=_N' {
>  loc c "inrange(st,st[`i'],end[`i'])"
>  loc c "`c'|inrange(end,st[`i'],end[`i'])"
>  loc c "`c'|inrange(st[`i'],st,end)"
>  loc c "`c'|inrange(end[`i'],st,end)"
>  g byte s=`c'
>  g long sum=sum(s)
>  replace nsimul=sum[_N] in `i'
>  drop s sum
> }
> g long others=nsimul-1
> compress
> li , noo clean
>
> The conditions for overlap with the current obs are collected in a
> local `c' and
>  g byte s=`c'
> determines which windows overlap with the current obs, but all that
> could be in one -gen- command (which might break awkwardly across
> lines in an email).
>
> On 4/19/07, Sebastian F. B�chte <sfbuechte@gmail.com> wrote:
> > I do not think there exist a _simple_ Stata command which would help
> > you achieving what you are asking for. But you could try to program it
> > yourself. I prepared some example code to show you how I would do it.
> > And as always I would expect that the code can be improved or maybe
> > some expert knows a Stata command that can do the trick.
> >
> > On 4/19/07, Jarl Svartsj� <j_svartsjo@yahoo.se> wrote:
> > > I have two date variables in my dataset, which define
> > > the start and end dates for a certain event. For each
> > > observation in the dataset, I'd like to count the
> > > number of other observations in the dataset that
> > > overlap with this event window.
> > >
>
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